Definition of sclera in US English:



  • The white outer layer of the eyeball. At the front of the eye it is continuous with the cornea.

    • ‘The remaining chapters include discussions of tumors of the orbit, eyelid, conjunctiva, cornea and sclera, uvea, and optic nerve.’
    • ‘Over the sclera lies the conjunctiva, a clear mucous membrane that protects the eye from becoming dry.’
    • ‘At the external border between the cornea and the sclera is the external scleral sulcus depression.’
    • ‘More anteriorly, the optic nerve is surrounded only by the smooth meningeal or inner layer of the dura, which blends with the sclera of the eyeball.’
    • ‘The limbus is the thin area that connects the cornea and the sclera, the white part of the eye.’


Late 19th century: modern Latin, from Greek sklēros ‘hard’.